Former State Department chief of staff Cheryl Mills told lawyers from the conservative legal watchdog group Judicial Watch she was "not aware" of any high-level discussion about Clinton's decision to use a private server for official communications, but her use of a personal account was understood, according to a deposition conducted last week that was released Tuesday.
Coming just days after an inspector general's report criticized Clinton for violating State Department policy and the Federal Records Act by using the private server, Mills' statements seem to suggest that Clinton and her advisers overestimated the department's ability to automatically preserve emails exchanged with other government employees.
Mills also refuted claims that the server was kept quiet, even though the IG report found no evidence that Clinton or her deputies sought approval for the unconventional account.
"Secretary Clinton emailed relatively a wide swath of folks, more than 100, certainly, in the department," Mills said. "And so her use of her email was not something that was unknown."
The nearly seven-hour deposition was conducted as part of an ongoing lawsuit filed by Judicial Watch against the State Department. While a federal judge barred the release of video from the deposition, the transcript was released on Tuesday.
Mills further suggested that Clinton's decision to use a personal email was motivated by "the convenience of being able to use a common device" and wasn't given much thought.
Clinton gave a similar explanation last year when news of her email practices first emerged.
"I opted for convenience to use my personal email account, which was allowed by the State Department, because I thought it would be easier to carry just one device for my work and for my personal emails instead of two," she told reporters at a news conference
But the IG report also highlighted an exchange between Clinton and her deputy chief of staff for operations that offers a potentially conflicting account of why Clinton's email was set up the way it was.
In November 2010, the report said, the deputy chief of staff of operations told Clinton that State Department employees were not receiving her emails.
"We should talk about putting you on State email or releasing your email address to the department so you are not going to spam," he emailed her.
Clinton responded: "Let's get separate address or device but I don't want any risk of the personal being accessible."
And Clinton's critics argue her decision to use the personal server exclusively was an attempt to circumvent the Federal Records Act, which requires personnel to preserve all official communications for archiving purposes, and to ensure they're available for public release under the Freedom of Information Act (FOIA).
It's also something the inspector general report criticized.
"At a minimum, Secretary Clinton should have surrendered all emails dealing with department business before leaving government service and, because she did not do so, she did not comply with the department's policies that were implemented in accordance with the Federal Records Act," the report said.
The IG report cites a particular email exchange from 2011, between Mills, Undersecretary for Management Patrick Kennedy, executive secretary Stephen Mull and deputy chief of staff Huma Abedin.
In the exchange, Mull proposes providing Clinton with a State Department BlackBerry after her personal device experienced malfunctions.
The device, which Mull noted "would mask her identity, but which would also be subject to FOIA requests," was rejected by Abedin, who replied that it "doesn't make a whole lot of sense."
Mills, in last week's deposition, was asked whether she and her colleagues had considered the fact that Clinton's emails would be concealed from FOIA officials unless the individuals she corresponded with were archiving them.
Mills said she was under the assumption that all Clinton's emails were being archived on the receiving end, but said she didn't give the matter much thought.
"Did anybody ever address any concerns that they couldn't access the secretary's account to respond to FOIA?" a lawyer for Judicial Watch asked.
"I'm not aware of it," Mills said. "They might have, and certainly from my standpoint I wish that had been something we thought about."
Mills said she only discussed the genesis of the account and its configuration with Clinton after both had left the State Department. Because she now represents Clinton as an attorney, she would not go into detail about those conversations.
The IG report found that that key officials "were not asked to approve or otherwise review the use of Secretary Clinton's server and that they had no knowledge of approval or review by other Department staff."
Clinton rejected that conclusion by pointing to other secretaries of state who used personal email, including Colin Powell, in a Tuesday interview with MSNBC. She also dismissed the report's assertion that officials in the State Department were discouraged from talking about her email practices.
The report specifically mentions an exchange between a staffer in the Bureau of Information Resource Management and her director. When the staffer raised concerns about the email server, the report says, "the director stated that the mission of (the bureau) is to support the secretary and instructed the staff never to speak of the secretary's personal email system again."
"I do not know who that person is or what that person might have said because it's not anything that I am aware of," Clinton told MSNBC. "I emailed with hundreds of people ... I certainly never instructed anyone to hide the fact that I was using a personal email."
Mills said she knew that Clinton was using a personal email account early on in her tenure at State, but viewed it as the "continuation of a practice (Clinton) had been using when she was senator."
Clinton's campaign has acknowledged that she transitioned from a personal AT&T email account to the clintonemail.com server shortly after she became secretary of state, an account Mills supported.
"I recall that there was a point at which she had to transition her email address and told everyone that she had a new email address," Mills said.
Because of the scope of Judicial Watch's lawsuit, last week's deposition focused primarily on the decision to set up a private server and the State Department's responsiveness to FOIA requests.
However, the group is also seeking to depose Mills as part a separate lawsuit related to the email issue and could expand on their line of questioning at that time. If the judge in that case approves their proposal, they will have another opportunity to question Mills, as well as Clinton, under oath.